Evaporated Titanium Films on Rocksalt

1967 ◽  
Vol 25 ◽  
pp. 296-297
Author(s):  
Frank E. Wawner ◽  
Kenneth R. Lawless
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Diffraction ◽  
Single Crystal ◽  
High Purity ◽  
Early Stages ◽  
Transmission Electron ◽  
Single Crystal Films ◽  
Crystal Films ◽  
Purity Titanium

Thin single crystal films of high purity titanium were needed in our laboratory for investigations of the early stages of the oxidation of titanium. Experiments were carried out to determine the feasibility of preparing single crystal titanium films of different orientations by evaporation onto the (100), (110) and (111) surfaces of rocksalt. The structures of these films were investigated by transmission electron microscopy and electron diffraction.

Evaporated Copper Deposits on Nickel Substrates

1967 ◽  
Vol 25 ◽  
pp. 298-299
Author(s):  
William L. Goodman ◽  
Kenneth R. Lawless
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Single Crystal ◽  
High Purity ◽  
Room Temperature ◽  
Copper Deposits ◽  
Transmission Electron ◽  
Crystal Films ◽  
Nickel Substrates ◽  
Thin Wedge

The structure of thin copper electrodeposits on single crystal nickel substrates has been previously studied in this laboratory. We thought it would be desirable to prepare similar bi-crystal films by the evaporation of copper onto nickel so that a comparison of the structures obtained by the two methods of deposition could be made. For this purpose, single crystal nickel films of (100), (110) and (111) orientations were prepared by evaporation onto heated (410°C) rocksalt substrates. Without breaking the vacuum, copper was evaporated in the form of a thin wedge onto the nickel surfaces after the nickel was cooled to room temperature. High purity (99.999%) metals were used, and these were thoroughly outgassed before evaporation. The thickness gradient of copper was obtained by moving a shutter between the substrate and the copper source during the evaporation. The resulting bi-crystal films were then stripped from the rocksalt and examined by transmission electron microscopy.

The Dodecagonal Quasicrystalline Telluride (Ta, V)1.6Te And Its Crystalline Approximant (TaV)97Te60

1998 ◽  
Vol 553 ◽  
Author(s):  
C. Reich ◽  
M. Conrad ◽  
F. Krumeich ◽  
B. Harbrecht
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Electron Diffraction ◽  
Single Crystal ◽  
Edge Length ◽  
X Ray ◽  
Transmission Electron ◽  
The Impact

AbstractThe dodecagonal (dd) quasicrystalline tantalum telluride dd Ta1.6Te and the crystalline approximant Ta97Te60 have been modified by partly replacing tantalum by vanadium. The impact of the substitution on the structures has been studied by X-ray and electron diffraction and by high-resolution transmission electron microscopy. The layered-type approximant structure of Ta83V14Te60 was determined by single crystal X-ray means. The partitioning of vanadium on 21 out of 29 crystallographically inequivalent metal sites is referred to, but not controlled by the Dirichlet domain volume available at the sites. A HRTEM projection of dd (Ta, V)1.6Te onto the dodecagonal plane is analysed with respect to the arrangement of (Ta, V)151Te74 clusters on the vertices of an irregular aperiodic square-triangle tiling, the edge length of which corresponds to the distance between the centres of two such clusters. The clusters comprise about 1 nm thick corrugated lamellae which are periodically stacked by weak Te-Te interactions.

Design of 2D-nanocrystals in water: preparation, structure and functionalization

2018 ◽  
Vol 90 (5) ◽  
pp. 833-844
Author(s):  
Leonid Aslanov ◽  
Valery Zakharov ◽  
Ksenia Paseshnichenko ◽  
Aleksandr Yatsenko ◽  
Andrey Orekhov ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Chemical Composition ◽  
High Resolution ◽  
Electron Diffraction ◽  
Single Crystal ◽  
Room Temperature ◽  
Energy Dispersive ◽  
X Ray ◽  
Transmission Electron

AbstractA new method for synthesis of 2D nanocrystals in water was proposed. The use of perfluorothiophenolate ions as surfactant allowed us to produce 2D single-crystal nanosheets of CaS at pH=9 and flat nanocrystals of PbS at pH=9 at room temperature. Mesocrystalline nanobelts of CdS and mesocrystals of PbS were obtained at pH=3–5 and pH=10–12, respectively. Morphology, structure and chemical composition of nanoparticles were characterized by high-resolution transmission electron microscopy, electron diffraction and energy dispersive X-ray spectroscopy. A mechanism of nanoparticles formation was discussed.

Compositional variation within some sedimentary chlorites and some comments on their origin

1985 ◽  
Vol 49 (352) ◽  
pp. 375-386 ◽  
Author(s):  
C. D. Curtis ◽  
C. R. Hughes ◽  
J. A. Whiteman ◽  
C. K. Whittle
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Diffraction ◽  
Single Crystal ◽  
Compositional Variation ◽  
Analytical Transmission Electron Microscopy ◽  
Decomposition Reactions ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
Crystal Electron

AbstractA range of authigenic sedimentary chlorites from sandstones has been studied by analytical transmission electron microscopy. Selected area (single crystal) electron diffraction patterns are of the Ib (β = 90°) polytype confirming the earlier observations of Hayes (1970).TEM analyses show all samples to be relatively rich in both Al and Fe. In the general formula (Mg,Fe,Al)n [Si8−xAlxO20](OH)16, x varies between 1.5 and 2.6; Fe/(Fe + Mg) between 0.47 and 0.83 and n between 10.80 and 11.54. Octahedral Al is close to 3 in this formulation and Fe2+ predominates over Fe3+. Swelling chlorites have significantly different compositions which are consistent with smectite/chlorite interstratifications.The Ib (β = 90°) polytype appears to be stable under conditions of moderate to deep burial. It replaces berthierine and swelling chlorites formed at lower temperatures. As commonly seen in grain coatings, however, it precipitates from porewater; solutes probably being contributed from several mineral decomposition reactions.

Orthorhombic Splitting and Chemical Etching of Ba2Ycu3O7-δ Crystal Surfaces

1989 ◽  
Vol 169 ◽  
Author(s):  
D. J. Werder ◽  
C. H. Chen ◽  
M. Gurvitch ◽  
B. Miller ◽  
L. F. Schneemeyer ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Diffraction ◽  
Single Crystal ◽  
Chemical Etching ◽  
Poor Quality ◽  
Crystal Surfaces ◽  
Surface Layers ◽  
The Poor ◽  
Transmission Electron

AbstractWe find by transmission electron diffraction (TED) that the orthorhombic splitting of the upper surface layers (< 1 μm) of single crystal Ba2YCu3O7-δ(YBCO) is reduced, differing by 10 to 30 percent from the bulk value. We also find by transmission electron microscopy (TEM) that in general the surfaces are of inferior quality, and thus, not representative of the bulk. These results have important consequences for those experiments that probe only the upper surface layers. By etching with either Br/ethanol or HClO4/NaClO4 the poor quality surfaces can be removed.

scholarly journals Pseudo-monocrystalline properties of cylindrical nanowires confinedly grown by electrodeposition in nanoporous alumina templates

RSC Advances ◽  
2017 ◽  
Vol 7 (23) ◽  
pp. 13817-13826 ◽  
Author(s):  
Enrique Díaz Barriga-Castro ◽  
Javier García ◽  
Raquel Mendoza-Reséndez ◽  
Víctor M. Prida ◽  
Carlos Luna
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Diffraction ◽  
Single Crystal ◽  
Nanoporous Alumina ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Nanoporous Alumina Templates

Four different cylindrical nanowires systems with single-crystal-like properties have been characterized by transmission electron microscopy and selected area electron diffraction (SAED) under different tilting angles.

Hydrothermal Synthesis of PbS Hollow Spheres with Single Crystal-Like Electron Diffraction Patterns

2008 ◽  
Vol 8 (1) ◽  
pp. 379-385
Author(s):  
Pingtang Zhao ◽  
Jinmin Wang ◽  
Guoe Chen ◽  
Zhou Xiao ◽  
Jing Zhou ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Diffraction ◽  
Single Crystal ◽  
Sodium Citrate ◽  
Near Infrared ◽  
Hydrothermal Process ◽  
Hollow Spheres ◽  
Transmission Electron ◽  
Diffraction Patterns

PbS hollow spheres were successfully prepared by a sodium citrate-assisted hydrothermal process at 120 °C for 12 h, employing lead acetate trihydrate, thiourea and sodium citrate as precursors. The diameter of PbS hollow spheres is 200–400 nm, which is composed of about 50–80 nm nanoparticles. The synthesized product was characterized by powder X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), electron diffraction (ED), Fourier transform-infrared (FT-IR) spectroscopy, ultraviolet-visible spectrometer (UV-vis) and near-infrared absorption spectrometer (NIR). The effects of the reaction conditions on morphologies of PbS structures were investigated. Star-shaped and flat PbS crystals were obtained by changing some experiment conditions. The results show that temperature, sodium citrate concentration, sulfur sources and solvent play key roles on the final morphologies formation of PbS crystals. Especially, ED result indicates that PbS hollow spheres hold single crystal-like electron diffraction patterns. And the possible formation mechanism of hollow spheres was proposed.

scholarly journals Synergy between transmission electron microscopy and powder diffraction: application to modulated structures

2015 ◽  
Vol 71 (2) ◽  
pp. 127-143 ◽  
Author(s):  
Dmitry Batuk ◽  
Maria Batuk ◽  
Artem M. Abakumov ◽  
Joke Hadermann
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Diffraction ◽  
Single Crystal ◽  
Powder Diffraction ◽  
Structure Refinement ◽  
Spectroscopic Techniques ◽  
X Ray ◽  
Transmission Electron

The crystal structure solution of modulated compounds is often very challenging, even using the well established methodology of single-crystal X-ray crystallography. This task becomes even more difficult for materials that cannot be prepared in a single-crystal form, so that only polycrystalline powders are available. This paper illustrates that the combined application of transmission electron microscopy (TEM) and powder diffraction is a possible solution to the problem. Using examples of anion-deficient perovskites modulated by periodic crystallographic shear planes, it is demonstrated what kind of local structural information can be obtained using various TEM techniques and how this information can be implemented in the crystal structure refinement against the powder diffraction data. The following TEM methods are discussed: electron diffraction (selected area electron diffraction, precession electron diffraction), imaging (conventional high-resolution TEM imaging, high-angle annular dark-field and annular bright-field scanning transmission electron microscopy) and state-of-the-art spectroscopic techniques (atomic resolution mapping using energy-dispersive X-ray analysis and electron energy loss spectroscopy).

Early stages of oxidation of aluminum nitride

1999 ◽  
Vol 14 (7) ◽  
pp. 2708-2711 ◽  
Author(s):  
Yongjun Geng ◽  
M. Grant Norton
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Diffraction ◽  
Aluminum Nitride ◽  
Oxide Layer ◽  
Orientation Relationship ◽  
Oxide Phase ◽  
Uniform Layer ◽  
Early Stages ◽  
Transmission Electron

The early stages of oxidation of aluminum nitride have been studied by transmission electron microscopy and electron diffraction. It has been found that the oxide layer grows by the Stranki–Krastonow mechanism, where an initial uniform layer is followed by island formation. The onset of oxidation occurs at 800 °C and the initial oxide phase that forms is γ–Al2O3, one of the transition aluminas. The orientation relationship between the oxide layer and the underlying nitride is (440)γ∥(1120)AIN and [112]γ∥[0110]AIN.

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